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. Author manuscript; available in PMC: 2016 Jan 1.
Published in final edited form as: Neurobiol Aging. 2014 Oct 17;36 Suppl 1:S178–S184. doi: 10.1016/j.neurobiolaging.2014.03.043

Algorithm for sampling from the residuals

 1: Sample ηijk independently from a standard Normal distribution, assuming no missing data;
 2: Compute εijk using the AR(1) model, imputing the values ηijk as residuals;
 3: Compute yijk using the model (3), imputing εijk as residuals;
 4: Determine the missing data for each biomarker with the following sampling procedure: Sample from a 2 state (not available (NA), not NA) non-homogeneous Markov chain indexed by the successive visits. The transition matrix was estimated separately for each status at baseline (N, MCI and AD) and before hand.
 5: Estimate all the parameters from the simulated dataset with missing data obtained at the last step using Alg. 1. Notate ck(m) the estimated parameter c for biomarker k at iteration m.